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0. L. RBDFIELD. TYPE DIE FOR MATRIX MAKING.

Patented June 10, 1890.

UNITED STATES PATENT OFFICE.

CASPER L. REDFIELD, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CHICAGO MATRIX MACHINE COMPANY.

TYPE-DIE FOR MATRIX-MAKING.

SPECIFICATION forming part of Letters Patent No. 429,866, dated June 10, 1890.

Application filed March 26, 1890. Serial No. 345,377- (No model.)

To all whom it may concern:

Be it known that I, CASPER L. REDFIELD, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Type-Dies for Matrix-Making, of which the following is a specification.

My invention relates to type-dies to be used for forming matrices by the successive imxo pression of the dies.

The object of the invention is to correct as far as possible the distortions in the impres sions caused by succeeding impressions, so that stereotype-plates may be cast therefrom having the desired printing-faces.

To illustrate my improvement, I have shown the efiect of making successive impressions in a matrix body with ordinary type dies. This appears in Figures 1, 2, 3, and 4, and in Figs. 5, 6, and 7 I have illustrated my improved form of type-die and shown the manner of its operation and the efiect of later upon earlier impressions.

Fig. 1 shows an ordinary type-die suspended over a matrix material; Fig. 2, the. die impressed in the matrix material. Fig. 3 shows the die impressed in the material adjacent to the first impression; Fig. 4, a third impression of the die adjacent to the second. Fig. 5

0 shows my improved form of die impressed into the matrix material; Fig. 6, a second impression adjacent to the first, and Fig. 7 a third impression being made adjacent to the second.

To formimpressions, the matrix material is supported upon an unyielding platen or anvil, (not shown,) which precludes expansion of the matrix material below its plane in that direction and causes such portions as are not compacted beneath the die to be pressed and distributed laterally, as indicated by arrows on the several drawings. A single impression, as would appear from Fig. 2, has its face (or bottom of the impression) on a plane parallel to the surfaces of the matrix material.

A second impression of the die in close proximity to the first impression, as shown in Fig. 3,produces a lateral spreading of the material under the die with the effect of raising the forward portion of the preceding impression above its original plane, and this second impression is in turn similarly aifected by the next impression, as shown in Fig. 4, and each impression is similarly distorted to a greater or less degree by the next following impression throughout the series to the last. To compensate for this unavoidable raising of the forward sides of the matrix-faces, I form my die-faces in such manner as to have the forward portion penetrate to a greater depth than the rear portion, so that when succeeding impressions are made the deeper portions of preceding impressions will be raised to the common plane-of their other portions.

It will be apparent that stereotype-plates cast from matrices having distorted impressions-such as shown in Figs. 3 and 4Ewould have each of the type-faces higher at one of its sides than the other, while from matrices having their type-faces on a common plane, as shown in Fig. 7, plates could be cast having type-faces on a level and adapted to produce good print.

In the drawings there is shown in vertical section a type-die 1, having twobranches 2 and 3, representing the two portions of a transverse section of the letter 0. The space intervening the two branches 2 and 3 is preferably deeply recessed, as shown at 4, so that a portion of the compressed matrix material may find a lodging-place there and not be crowded away laterally from the die. Both sides of the stems or branches 2 and 3 are provided with shoulders, those 5 at forward sides being nearer the face than those 6 at they rear sides. These shoulders serve to widen the openings back of the face-impressions, and thus enable better plates to be cast and avoid having the matrix stick to the casting.

The matrix material is designated by 7, and the type-impressions by 8. The inclination of the plane representing the face of a single letter relative to the common plane of the line of impressions is largely exaggerated in the drawings, so as to more clearly illustrate the evil effects of the displacement. In characters having more than two branches, as In or w, the displacement would of course affect, principally, the forward branch. To 'overcome this displacement of the plane of impressions, I make my type-dies with inclined faces, the inclinations being in the direction relative to the plane of the printing opposite to that produced by the displacement in forming the impression-that is, the inclination is downward from the rear to the forward portion of the type-faces, as clearly shown in the dies in Figs. 5, (3, and 7.

The inclination of the type-faces may be made equal to the distortion occasioned in the impressions; but by so doing the last impression of the line of print will, as is apparent, remain deeper than the others, which will be an objection. I preferably make the degree of this inclination about half as great as the distortion caused by the successive impressions. The result of this is that the displace ment of the plantingaces of each character is divided so as to be partly above and partly below the printing-plane of the line. After a stereotype is cast from such impressions the printing-faces may be given a slight finishing to bring them all to the same plane.

The process for formin g matrices for stereotype-plates herein partially disclosed is re served as subject-matter for another application, Serial No. 345,378, filed by me March 26, 1890, and the invention relative to the use of shoulders in rear of the type-faces is also reserved to be claimed in applications for patcut by me, Serial No. 336,849, filed January 13, 1890, and Serial No. 332,756, filed December (J, 1889.

Having described my invention, what I claim is- 1. A type-die having its printing-face inclined, for the purpose set forth.

2. A type-die having the forward portion of its printing-face adapted to make deeper impressions than the rear portion, substantially as set forth.

3. A series of type-dies having their faces formed to penetrate deeper at the forward than the rear portion, whereby distortions in the successive impressions are corrected, sub stantially as set forth.

4. A type-die the rear portion of the face of which is adapted to displace proportionately less matrix material than the forward portion, substantially as set forth.

5. A type-die having shoulders in rear of the face and having the face inclined toward the forward side, substantially as set forth.

' (3. A type-die having a recess between its branches and shoulders at both sides of the branches, substantially as set forth.

CASPER L. REDFIELD.

Vitnesses:

EDWARD B. SPRINGER,

GRAHAM P. JONES. 

